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VRV

Q1)

Are there any constrain on the distance between indoor and outdoor units?

 

The followings have to be considered and confirmed with the supplier when installing a VRV/VRF system:

  • Maximum allowable refrigerant pipe length
  • Maximum allowable distance and height between the outdoor unit and the most remote indoor unit in the system
  • Maximum allowable distance and height between indoor units.

Water-cooled air conditioning system

Q1)

How much energy can the water-cooled air conditioning system save compared to the air-cooled air conditioning system?

 

According to a study conducted by the EMSD, the energy saving from various types of the water-cooled air conditioning system ranges from 14% to 35%.

   
Q2)

What will be the capital cost for the conversion of air-cooled air conditioning system to water-cooled air conditioning system with cooling towers?

  Because of the great variance of site and system constraints, capital costs of conversion from existing air-cooled air conditioning system to evaporative water-cooled air conditioning system cannot be given. However, it is noted that the capital cost of evaporative water-cooled air conditioning system is about 15% lower than air-cooled air conditioning system on new system basis. Hence, if the conversion of existing air-cooled air conditioning system to evaporative water-cooled air conditioning system can be planned at the end of economic life of existing air-cooled air conditioning system, it is likely to have a reduction in replacement cost for choosing evaporative water-cooled air conditioning system in lieu of air-cooled air conditioning system. The operating life of air-cooled packaged chiller condensers is around 10 to 15 years while for fresh water cooling towers is around 15 to 20 years.
   
   

Thermal wheel and Desiccant total energy heat recovery wheel

Q1)

What are the benefits of using desiccant in an air-conditioning system?

 

The use of desiccant components to an HVAC system directly removes the water vapour (latent heat) from the air, overcoming dehumidification limitations of cooling coils. Desiccants enable independent control of temperature and humidity, improving HVAC system efficiency.

Using desiccants in buildings can also improve, or even eliminate those airborne particles and gases that cause sick-building syndrome, dust mites, and overall discomfort in building environments.

For more benefits and details of Heat wheel with desiccant dehumidifier, please click here.

Radiant ceiling cooling

Q1)

Since chilled water pipes lie close to the ceiling surfaces or in panels in this system, will this cause any condensation problem?

 

Condensation may occur on the cooled ceiling surfaces if the moisture content of the indoor air is high. To avoid condensation on the chilled panels, a separate system to maintain the dew point of indoor air below the panel temperature is required. Since outdoor makeup air is the dominant source of moisture load in buildings, the separate system can dehumidify the outdoor air in advance. Therefore a low moisture content of the indoor air can be maintained.

Thermal energy storage (TES) system

Q1)

What is the benefit of Thermal energy storage system?

 

Thermal energy storage system allow shifting of the peak load to nighttime, it also reduces the size and initial cost of cooling systems. Therefore, the capacity of the cooling system can be much lower than the peak cooling load of the building.

   
Q2)

What are the applications of TES system?

 

TES may be economical if one or more of the following conditions exist:

  • High peak-demand cost incurred by the power company
  • Power company charges more for energy use during peak periods of day and less during off-peak periods
  • High daily load variations
  • Short duration loads
  • Capacity of cooling equipment has trouble handling peak loads